/*
* This version is for use with mbufs on Ultrix systems.
*
- * $Id: bsd-comp.c,v 1.2 1994/11/28 01:41:29 paulus Exp $
+ * $Id: bsd-comp.c,v 1.8 1996/08/28 06:32:00 paulus Exp $
*/
#include "../h/param.h"
#define PACKETPTR struct mbuf *
#include "ppp-comp.h"
+#if DO_BSD_COMPRESS
+
+#define BSD_LITTLE_ENDIAN /* all Ultrix machines are little-endian */
+
/*
* PPP "BSD compress" compression
* The differences between this compression and the classic BSD LZW
* compression is not going well.
*/
-/*
- * Macros to extract protocol version and number of bits
- * from the third byte of the BSD Compress CCP configuration option.
- */
-#define BSD_VERSION(x) ((x) >> 5)
-#define BSD_NBITS(x) ((x) & 0x1F)
-
-#define BSD_CURRENT_VERSION 1
-
/*
* A dictionary for doing BSD compress.
*/
u_char debug;
u_char unit;
u_short seqno; /* sequence # of next packet */
+ u_int hdrlen; /* header length to preallocate */
u_int mru;
u_int maxmaxcode; /* largest valid code */
u_int max_ent; /* largest code in use */
union { /* hash value */
u_int32_t fcode;
struct {
-#if BYTE_ORDER == LITTLE_ENDIAN
+#ifdef BSD_LITTLE_ENDIAN
u_short prefix; /* preceding code */
u_char suffix; /* last character of new code */
u_char pad;
};
#define BSD_OVHD 2 /* BSD compress overhead/packet */
-#define MIN_BSD_BITS 9
-#define BSD_INIT_BITS MIN_BSD_BITS
-#define MAX_BSD_BITS 15
+#define BSD_INIT_BITS BSD_MIN_BITS
static void *bsd_comp_alloc __P((u_char *options, int opt_len));
static void *bsd_decomp_alloc __P((u_char *options, int opt_len));
static void bsd_free __P((void *state));
static int bsd_comp_init __P((void *state, u_char *options, int opt_len,
- int unit, int debug));
+ int unit, int hdrlen, int debug));
static int bsd_decomp_init __P((void *state, u_char *options, int opt_len,
- int unit, int mru, int debug));
+ int unit, int hdrlen, int mru, int debug));
static int bsd_compress __P((void *state, struct mbuf **mret,
struct mbuf *mp, int slen, int maxolen));
static void bsd_incomp __P((void *state, struct mbuf *dmsg));
* Procedures exported to if_ppp.c.
*/
struct compressor ppp_bsd_compress = {
- 0x21, /* compress_proto */
+ CI_BSD_COMPRESS, /* compress_proto */
bsd_comp_alloc, /* comp_alloc */
bsd_free, /* comp_free */
bsd_comp_init, /* comp_init */
#define LAST 255
#define MAXCODE(b) ((1 << (b)) - 1)
-#define BADCODEM1 MAXCODE(MAX_BSD_BITS);
+#define BADCODEM1 MAXCODE(BSD_MAX_BITS)
#define BSD_HASH(prefix,suffix,hshift) ((((u_int32_t)(suffix)) << (hshift)) \
^ (u_int32_t)(prefix))
#define RATIO_SCALE (1<<RATIO_SCALE_LOG)
#define RATIO_MAX (0x7fffffff>>RATIO_SCALE_LOG)
+static void bsd_clear __P((struct bsd_db *));
+static int bsd_check __P((struct bsd_db *));
+static void *bsd_alloc __P((u_char *, int, int));
+static int bsd_init __P((struct bsd_db *, u_char *, int, int, int, int,
+ int, int));
+
/*
* clear the dictionary
*/
db->ratio = 0;
db->bytes_out = 0;
db->in_count = 0;
- db->incomp_count = 0;
db->checkpoint = CHECK_GAP;
}
u_int newlen, hsize, hshift, maxmaxcode;
struct bsd_db *db;
- if (opt_len != 3 || options[0] != 0x21 || options[1] != 3
+ if (opt_len < CILEN_BSD_COMPRESS || options[0] != CI_BSD_COMPRESS
+ || options[1] != CILEN_BSD_COMPRESS
|| BSD_VERSION(options[2]) != BSD_CURRENT_VERSION)
return NULL;
bits = BSD_NBITS(options[2]);
* Initialize the database.
*/
static int
-bsd_init(db, options, opt_len, unit, mru, debug, decomp)
+bsd_init(db, options, opt_len, unit, hdrlen, mru, debug, decomp)
struct bsd_db *db;
u_char *options;
- int opt_len, unit, mru, debug, decomp;
+ int opt_len, unit, hdrlen, mru, debug, decomp;
{
int i;
- if (opt_len != 3 || options[0] != 0x21 || options[1] != 3
+ if (opt_len < CILEN_BSD_COMPRESS || options[0] != CI_BSD_COMPRESS
+ || options[1] != CILEN_BSD_COMPRESS
|| BSD_VERSION(options[2]) != BSD_CURRENT_VERSION
|| BSD_NBITS(options[2]) != db->maxbits
|| decomp && db->lens == NULL)
}
db->unit = unit;
+ db->hdrlen = hdrlen;
db->mru = mru;
#ifndef DEBUG
if (debug)
}
static int
-bsd_comp_init(state, options, opt_len, unit, debug)
+bsd_comp_init(state, options, opt_len, unit, hdrlen, debug)
void *state;
u_char *options;
- int opt_len, unit, debug;
+ int opt_len, unit, hdrlen, debug;
{
return bsd_init((struct bsd_db *) state, options, opt_len,
- unit, 0, debug, 0);
+ unit, hdrlen, 0, debug, 0);
}
static int
-bsd_decomp_init(state, options, opt_len, unit, mru, debug)
+bsd_decomp_init(state, options, opt_len, unit, hdrlen, mru, debug)
void *state;
u_char *options;
- int opt_len, unit, mru, debug;
+ int opt_len, unit, hdrlen, mru, debug;
{
return bsd_init((struct bsd_db *) state, options, opt_len,
- unit, mru, debug, 1);
+ unit, hdrlen, mru, debug, 1);
}
u_char *rptr, *wptr;
u_char *cp_end;
int olen;
- struct mbuf *m, **mnp, *clp;
+ struct mbuf *m, *clp;
#define PUTBYTE(v) { \
++olen; \
MGET(m, M_DONTWAIT, MT_DATA);
*mret = m;
if (m != NULL) {
- if (maxolen > MLEN) {
+ if (maxolen + db->hdrlen > MLEN) {
MCLGET(m, clp);
}
+ m->m_off += db->hdrlen;
m->m_len = 0;
wptr = mtod(m, u_char *);
cp_end = wptr + M_TRAILINGSPACE(m);
if (ent < 0x21 || ent > 0xf9)
return;
- db->incomp_count++;
db->seqno++;
ilen = 1; /* count the protocol as 1 byte */
rptr += PPP_HDRLEN;
struct mbuf *m, *dmp, *mret;
int adrs, ctrl, ilen;
int space, codelen, extra;
- struct mbuf *last, *clp;
+ struct mbuf *clp;
/*
* Save the address/control from the PPP header
* Check the sequence number and give up if it differs from
* the value we're expecting.
*/
- if (seq != db->seqno++) {
+ if (seq != db->seqno) {
if (db->debug)
printf("bsd_decomp%d: bad sequence # %d, expected %d\n",
db->unit, seq, db->seqno - 1);
return DECOMP_ERROR;
}
+ ++db->seqno;
/*
* Allocate one mbuf to start with.
dmp->m_next = NULL;
MCLGET(dmp, clp);
dmp->m_len = 0;
+ dmp->m_off += db->hdrlen;
wptr = mtod(dmp, u_char *);
space = M_TRAILINGSPACE(dmp) - PPP_HDRLEN + 1;
return DECOMP_FATALERROR;
#endif /* DEBUG */
}
+#endif /* DO_BSD_COMPRESS */